Electrosurgery involves the application of radio frequency energy to achieve a tissue effect. The electrosurgical energy is generated by an electrosurgical generator which is applied to the tissue either by monopolar or bipolar circuits. In monopolar, there is a small active electrode directed toward the tissue to be treated and to complete the circuit there is a large patient return electrode applied somewhere to the patient's body. The power density through the patient return electrode is relatively small so that there is no tissue effect thereat. In bipolar, a pair of electrodes are spaced close together with tissue therebetween. In certain circumstances the bipolar electrodes are moveable toward and away from one another.
Electrosurgery can be used for cutting, coagulating or a combination thereof called blend. Coagulation is often described as desiccation of the tissue and fulguration of the tissue. Fulguration is the electrical arcing from the active electrode toward various locations, on the patient's tissue, in the vicinity of the active electrode. Typically when the arcs travel through air, they reach the tissue in a random, non-predictable manner. In many cases arcs leave the active electrode in a trajectory emanating generally along the axis of the active electrode, but before they contact the tissue their paths may vary due to the impedance at the tissue near the active electrode. The resulting fulguration is an uneven or randomly concentrated or irregularly distributed delivery of the energy in each arc, thus producing an uneven or variable coagulation of the tissue desiccated thereat. This is unsatisfactory from the point of view of producing a controlled and preferred level of eschar.
Ionized gases have been used to direct the electrosurgical energy in a more controlled manner. U.S. Pat. No. 4,781,175 deals particularly with that approach. A disadvantage of using ionized gas is the possibility of formation of embolisms within the blood of the patient being treated. In addition, there is the potential for the gas being misdirected and forming a plasma torch either through a leak in the electrosurgical handpiece or pencil or when delivered in a laparoscopic procedure within the trocar which provides entry into the body cavity. Another problem with ionized gas is that the electrosurgery and the gas flow are essentially concurrent in the form of a plasma flame that is used to fulgurate and desiccate tissue at which it is aimed. The aiming or positioning of the plasma flame on the desired target tissue is uncertain until activated. Therefore, the pinpointing of the spot at which to initiate the effect is not readily determinable until the electrosurgical energy is delivered.
U.S. Pat. No. 5,011,483 discloses a device which is in the form of a handpiece housing from which electrosurgical and laser energy may be delivered alternatively for selective use thereof. In connection with laparoscopic procedures, an elongate hollow shaft is disclosed for a wave guide to conduct the laser energy. The wave guide may be flexible and one preferred form is a fiber optic. The disclosure of the reference is largely limited to the alternate use of laser or electrosurgery. There is no discussion or disclosure of concurrent delivery.
Japanese patent JP57-69853 relates to a laser device which radiates a laser beam to mark the position for subsequent application of laser surgery. No electrosurgery is disclosed and the use of a laser with electrosurgery even for pinpointing is not taught. Japanese patent JP57-69790 has a laser radiation apparatus with a laser oscillator including a light guide and a generator for radiating visible light for positioning. These Japanese patents are used to direct the laser energy and do not teach the concurrent use of laser energy and electrosurgery energy.
U.S. Pat. No. 5,324,254 discloses a single laparoscopic instrument capable of supplying either laser radiation or electrosurgical energy. An electrosurgical electrode is provided at the distal end of the instrument for electrosurgical procedures. A side port located near the proximate end of the instrument allows for the passage of a laser fiberoptic bundle, thereby allowing for laser surgery. The patent does not teach the concurrent use of laser energy and electrosurgical energy in a synchronized manner.
An article entitled How Lasers Might Control Lightning Strikes, appearing in Laser Focus World, November 1993, pages 113-123, by Zhao, Xin Miao and Daniels, Jean-Claude, discloses how lasers establish an ionized pathway for electric arc transmission. Ordinary optical beams produce little ionization in air or an essentially weak plasma which can be used to direct electrical discharges.
The application of any form of atmospheric ionization to direct electrosurgical beams either statically or dynamically has not been disclosed in the prior technology.